Remotely controlled electrical power generating system

ABSTRACT

An externally-controllable electrical power generating system for providing auxiliary or backup power to a load bus or device. The system may be used indoors, and generally includes a power source comprising a first DC output, an electrical storage unit comprising a DC input coupled to the first DC output of the power source, the electrical storage unit further comprising a second DC output. An inverter coupled to the second DC output receives power, the inverter having a first AC output that can be synchronized with an AC load bus or AC grid. The system includes a contactor connected between the first AC output and an AC load bus, and is controllable with an external controller operated by a utility or a managing entity, such that the external controller can enable the controller to connect or disconnect the contactor.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation-in-part of U.S. applicationSer. No. 17/325,713 filed on May 20, 2021, which is a continuation ofU.S. application Ser. No. 16/745,448 filed on Jan. 17, 2020 now issuedas U.S. Pat. No. 11,018,508. The present application also claimspriority to U.S. Provisional Application No. 63/131,970 filed on Dec.30, 2020. Each of the aforementioned patent applications is hereinincorporated by reference in their entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable to this application.

BACKGROUND Field

Example embodiments in general relate to a remotely controlledelectrical power generating system for providing safe and efficientbackup, emergency, or supplemental AC power.

Related Art

Any discussion of the related art throughout the specification should inno way be considered as an admission that such related art is widelyknown or forms part of common general knowledge in the field.

Conventional backup electrical generators, especially those suited forrelatively high power output, may comprise diesel or gasoline engines.Such generators may be less desirable for operation in closed spaces,such as inside of buildings, shipboard, in tunnels, etc., due to noiseconsiderations, the danger of storing and handling fuel, and toxicexhaust fumes. Further, many generators are not capable of using abuilding's in-place wiring to provide power within the building.

Conventional utility demand management in the past has typically beenimplemented by systems that shut off selected electrical appliances andloads, which may inconvenience customers.

SUMMARY

An example embodiment is directed to a remotely controlled electricalpower generating system. The remotely controlled electrical powergenerating system includes a fuel cell comprising a first DC output; anelectrical storage unit comprising a DC input coupled to the first DCoutput of the fuel cell, the electrical storage unit further comprisinga second DC output; an inverter coupled to the second DC output of theelectrical storage unit to receive power, the inverter comprising afirst AC output; a contactor connected between the first AC output andan AC load bus, the AC load bus comprising an AC voltage; and acontroller comprising inputs adapted to sense a phase, a frequency, anda magnitude of the first AC output and the AC voltage. Alternatively,the primary power source may be or include a generator or alternator anda rectifier to provide a DC output to the inverter, so that afuel-powered generator can be used in place of a fuel cell to power thesystem.

The controller controls the phase, the frequency, and the magnitude ofthe first AC output of the inverter. The controller may further comprisean output command to selectively activate the contactor when arelationship between the phase, the frequency, and the magnitude of thefirst AC output and the AC voltage are substantially matched.

In some example embodiments, the controller is usable to adjust thephase, the frequency, and the magnitude of the first AC output of theinverter to cause them to substantially match the phase, the frequency,and the magnitude of the AC voltage on the AC load bus before thecontroller sends the output command. In still other embodiments, thecontroller is further adapted to communicate with a remote computingdevice, which may be a wired or a wireless device. The remote computingdevice is adapted to send a command to the controller to connect theelectrical power generating system to the AC load bus, and it may alsoperform other functions. As an example, the remote computing device maybe adapted to allow a user to monitor operating conditions of theelectrical power generating system. The remote computing device may alsobe adapted to send a command to the controller to disconnect theelectrical power generating system from the AC load bus, or to remotelyshut down the electrical power generating system.

In still other example embodiments of the electrical power generatingsystem activating the contactor causes the first AC output to beconnected in parallel with the AC voltage on the AC load bus.

Still further, the electrical power generating system may comprise asecond fuel cell comprising a third DC output, a second electricalstorage unit comprising a second DC input coupled to the third DC outputof the second fuel cell, the second electrical storage unit furthercomprising a fourth DC output. The embodiment may also comprise a secondinverter coupled to the fourth DC output of the second electricalstorage unit to receive power, the second inverter comprising a secondAC output, and a second contactor connected between the second AC outputand the AC load bus, and a second controller comprising second inputsadapted to sense a second phase, a second frequency, and a secondmagnitude of the second AC output and the AC voltage, wherein the secondcontroller controls the second phase, the second frequency, and thesecond magnitude of the second AC output of the second inverter.

The second controller may further comprise a second output command toselectively activate the second contactor when a relationship betweenthe phase, the frequency, and the magnitude of the second AC output andthe AC voltage are substantially matched. In some embodiments,activating the second contactor causes the second AC output to beconnected in parallel with the first AC output.

Further, the second controller may adjust the phase, the frequency, andthe magnitude of the second AC output to cause them to substantiallymatch the phase, the frequency, and the magnitude of the AC voltage onthe AC load bus before the second controller sends the output command.

In an example embodiment, the second controller is further adapted tocommunicate with a remote computing device, which may be the same deviceor a separate device from the one that communicates with the firstcontroller. Further, the remote computing device may be a wired or awireless device. The remote computing device may also be adapted to senda command to the second controller to connect the second AC output tothe AC load bus. For example, the remote computing device may be adaptedto send a command to the second controller to activate or deactivate thesecond contactor.

Further, the remote computing device may be adapted to allow a user tomonitor operating conditions of the electrical power generating system,and specifically, either of two or more generators being used, singly orin parallel, to provide power to the AC load bus. In addition, theremote computing device may be adapted to send a command to the secondcontroller to shut down the second fuel cell.

Using the electrical power generating system may comprise activating thefuel cell, monitoring the phase, frequency, and magnitude of the ACvoltage of the AC load bus, and adjusting the phase, frequency, andmagnitude of the first or second AC output, or both of them, tosubstantially match the phase, frequency, and magnitude of the ACvoltage of the AC load bus, and activating the contactor or contactorsto connect the first, second, or both AC outputs to the AC load bus.

There has thus been outlined, rather broadly, some of the embodiments ofthe electrical power generating system in order that the detaileddescription thereof may be better understood, and in order that thepresent contribution to the art may be better appreciated. There areadditional embodiments of the electrical power generating system thatwill be described hereinafter and that will form the subject matter ofthe claims appended hereto. In this respect, before explaining at leastone embodiment of the electrical power generating system in detail, itis to be understood that the electrical power generating system is notlimited in its application to the details of construction or to thearrangements of the components set forth in the following description orillustrated in the drawings. The electrical power generating system iscapable of other embodiments and of being practiced and carried out invarious ways. Also, it is to be understood that the phraseology andterminology employed herein are for the purpose of the description andshould not be regarded as limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

Example embodiments will become more fully understood from the detaileddescription given herein below and the accompanying drawings, whereinlike elements are represented by like reference characters, which aregiven by way of illustration only and thus are not limitative of theexample embodiments herein.

FIG. 1 is a simplified block diagram of an electrical power generatingsystem in accordance with an example embodiment.

FIG. 2 is another simplified block diagram of an electrical powergenerating system in accordance with an example embodiment.

FIG. 3 is a perspective view illustrating a use of an electrical powergenerating system in accordance with an example embodiment.

FIG. 4 is another perspective view illustrating a portable electricalpower generating system in accordance with an example embodiment.

FIG. 5 is another perspective view illustrating a portable electricalpower generating system in accordance with an example embodiment.

FIG. 6 is a simplified flow chart illustrating operation of anelectrical power generating system in accordance with an exampleembodiment.

FIG. 7 is another simplified block diagram of an electrical powergenerating system in accordance with an example embodiment.

FIG. 8 is another simplified flow chart illustrating a use of anelectrical power generating system in accordance with an exampleembodiment.

FIG. 9 is a front view of a display usable with an electrical powergenerating system in accordance with an example embodiment.

FIG. 10 illustrates voltage waveforms of an electrical power generatingsystem in accordance with an example embodiment.

FIG. 11 is another illustration of voltage waveforms of an electricalpower generating system in accordance with an example embodiment.

FIG. 12 is another illustration of voltage waveforms of an electricalpower generating system in accordance with an example embodiment.

FIG. 13 is another simplified block diagram of an electrical powergenerating system in accordance with another example embodiment.

FIG. 14 is another simplified block diagram of an electrical powergenerating system in accordance with another example embodiment.

DETAILED DESCRIPTION

A. Overview.

An example electrical power generating system 10 generally comprises afuel cell 30 comprising a first DC output 32, an electrical storage unit40 comprising a DC input 42 coupled to the first DC output 32 of thefuel cell 30, the electrical storage unit 40 further comprising a secondDC output 44, an inverter 50 coupled to the second DC output 44 of theelectrical storage unit 40 to receive power, the inverter 50 comprisinga first AC output 52, a contactor 60 connected between the first ACoutput 52 and an AC load bus 66, the AC load bus 66 comprising an ACvoltage, and a controller 70 comprising inputs 62, 64 adapted to sense aphase, a frequency, and a magnitude of the first AC output 52 and the ACvoltage on the load bus 66, respectively.

A different power source 100 may also be used in place of a fuel cell30, and may comprise a mechanical generator or alternator combined witha rectifier. The power source 100 may also include an electrical storageunit 40 and an inverter 50, such that the power source 100 can be usedto receive fuel from a fuel source 102 via fuel line 104, and thusprovide the first AC output 52. Telemetry component 80 may have acontrol bus to power source 100, and may be used to control the powersource 100 as discussed herein. The system 10 may also include asynchronizer 106 between the power source and the AC main 90 or an ACload 92, to allow the power source 100 to provide AC power that issynchronized in phase, frequency, and magnitude.

The controller 70 controls the phase, the frequency, and the magnitudeof the first AC output 52 of the inverter. The controller 70 may furthercomprise an output command 72 to selectively activate the contactor 60when a relationship between the phase, the frequency, and the magnitudeof the first AC output 52 and the AC voltage are substantially matched.

In some example embodiments, the controller 70 is usable to adjust thephase, the frequency, and the magnitude of the first AC output 52 of theinverter 50 to cause them to substantially match the phase, thefrequency, and the magnitude of the AC voltage on the AC load bus 66before the controller 70 sends the output command. In still otherembodiments, the controller 70 is further adapted to communicate with aremote computing device 95, which may be a wired or a wireless device.The remote computing device 95 is adapted to send a command to thecontroller 70 to connect the electrical power generating system 10 tothe AC load bus 66, and it may also perform other functions. As anexample, the remote computing device 95 may be adapted to allow a userto monitor operating conditions of the electrical power generatingsystem 10. The remote computing device 95 may also be adapted to send acommand to the controller 70 to disconnect the electrical powergenerating system 10 from the AC load bus 66, or to remotely shut downthe electrical power generating system 10.

The system 10 can also be controlled remotely by an external controller,such as utility control system 96, which can communicate with andprovide input to the controller 70, and also telemetry component 80. Theexternal controller can be operated by a utility or a managing entity,such that the external controller can enable the controller 70 toactivate the output command to the contactor 60.

In still other example embodiments of the electrical power generatingsystem 10, activating the contactor 60 causes the first AC output 52 tobe connected in parallel with the AC voltage on the AC load bus 66,which is possible due to the synchronization of the voltage parametersas discussed above.

Further, the electrical power generating system 10 may include more thanone power source subsystem, such as a second fuel cell or power source(e.g., generator or alternator), inverter, and the other componentsmentioned above, and the components or subsystems can be connected inparallel. As an example, two or more subsystems of the present system 10may be connected in parallel over an AC load bus 66, such as a buildingor house's existing wiring, effectively using that wiring as amicro-microgrid. In such a case, one, two, or more subsystems can beconnected to the AC load bus 66 while the bus is also powered by an ACmain power source 90, such as a city's electrical grid, with theelectrical power generating system 10 adding additional, local powercapacity to the wiring. The system 10 can also be used to provide backupor emergency power to the AC load bus 66 with no other power sourceavailable. Use of existing wiring as a micro-microgrid is possiblebecause the system uses analog power line synchronization for matchingor substantially matching voltage, frequency, and phase of the generatedAC output to any voltage present on the existing AC load bus, eitherfrom the AC main source 90 or another fuel cell/inverter of system 10connected in parallel. An electrical power generating system 10 of thepresent system may comprise one or more generators, since each may besubstantially the same, and because each may be connected to the AC loadbus 66 at the same time, thus becoming part of the overall system 10.For indoor operations, the system 10 can be entirely contained on aportable, wheeled cart 14, sized to readily fit through doorways andhallways of hotels, industrial buildings, etc. Furthermore, the systemcan easily be connected to existing building wiring (e.g., conventionaland standard 120V building or residential wiring) by providing an outputin the form of standard 120V power cords that can simply be plugged intoone or more power outlets of the existing wiring system, thus using theexisting wiring as a micro-microgrid with no special wiring equipmentneeded.

As an alternative to a portable setup, the remote- orexternally-controllable electrical power generating system can bepermanently installed. If so, it may be installed in a mechanical roomof a building or residence, next to the heating system and the mainelectrical panel, which allows the AC output of the system to beconnected to the building's or house's wiring, through a contactor thatallows for paralleling or isolating connections. For buildings that areheated using propane or natural gas, the gas line that is connected tothe furnace and heating elements may be connected to the reformer, or toa generator (i.e., if a generator of the system is a natural gasgenerator). The purpose of the reformer is to locally produce hydrogenof purity and volume sufficient for the fuel cell system to power thebuilding, or to provide supplemental power to the building. Thebyproduct of the reformer may be vented to the exterior of the building,and may use the same venting system as the heating system of thebuilding.

The system also includes a telemetry component 80 for remote monitoringand system management. For example, parameters such as run time, fuelamount, power output, output voltage, output current, etc., may bemonitored via telemetry. The telemetry component 80 also allows theremote computing device 95, such as a wireless phone, laptop, desktopcomputer, etc., to remotely start the system or any subsystem, shut downthe system, or to connect or disconnect any individual contactor orgroup of contactors to the micro-microgrid.

One possible physical configuration of the electrical power generatingsystem 10, or a subsystem (if more than one generating unit is to beused to supply power) is shown in FIGS. 4 and 5 . As shown in FIG. 4 ,all the components of a single unit can be mounted on a wheeled cart 14that is sized to fit in doorways and hallways of buildings, such ashotels or commercial establishments. One possible arrangement of themajor physical components is shown in FIG. 5 , which is alsorepresentative of the main components shown in FIG. 1 . The power outputof an electrical power generating system 10 can be supplied overordinary power cords that can be plugged into a building's existingoutlets, as shown in FIG. 3 , so that no special connections arerequired for the supply of auxiliary or emergency power.

B. Fuel Cell.

The electrical power generating system 10 may make use of compressedhydrogen gas 20 as a source for the fuel cell 30. Compressed hydrogengas is readily available from industrial gas suppliers. The hydrogen gas20 is kept in a storage tank or tanks of the system 10, and is regulatedto low pressures and provided over a supply line 26 to a fuel cell 30,as generally shown in FIG. 1 . Compressed hydrogen gas is easy to useand transport, and provides for economical operation of the fuel cell30. The fuel system includes connections of the fuel from storagevessels to generators, and can further include manifolds, regulators,shutoff valves, purge valves, and a tubing system to prevent leakage ofhydrogen and prevent the introduction of contaminants.

For indoor use, using purified hydrogen as a fuel source for the inputof a fuel cell or cells has distinct advantages over other sources. Forexample, some fuel cell systems use or propose reformers to providehydrogen from a liquid feedstock. However, the turn-on time forreformers is relatively long. For example, based on currenttechnologies, it may take eight to twelve hours to reach thetemperatures needed to produce hydrogen from a liquid feedstock. If areformer is used, the feedstock may be a liquid source (such as amethanol-deionized water blend), natural gas, propane, or other sourceof hydrocarbons that may be reformed into hydrogen. The output of thereformer is hydrogen gas, which can either be stored in a pressurevessel (e.g., a storage vessel) or connected directly to the hydrogeninput of one or more fuel cells.

The fuel cell or cells combine hydrogen and atmospheric oxygen toproduce electricity, with additional byproducts of water vapor and heat.In an example embodiment, the source for the atmospheric oxygen may bevented from the exterior of the building, using an air exchanger orother venting system. This venting may or may not be the same ventingused for the delivery of fresh air to a natural gas or propane heatingsystem if such a system is installed in the building. The heat createdby the fuel cell may advantageously be used in the interior of thebuilding as a heat source during cold outdoor temperatures, or may bevented to the exterior of the building in the event that heat is notdesired. In addition, the fuel cell or cells may use an advanced coolingsystem, such as a liquid cooled or an evaporatively cooled system todissipate the heat created by the fuel cell(s). This time may be reducedif a heater is continually operated, but continuous use of a heater mayconsume, for example, 200 W to 500 W in standby mode without anyproductive use being made of the system, thus greatly reducing theoverall efficiency, especially for a system used to produce, forexample, a relatively small amount of power, such as 2 kW.

Further, the process of reforming liquid fuel is not zero emission, andproduces CO and CO₂, which can be dangerous in indoor or confinedenvironments. In contrast, hydrogen fuel cells produce no harmfulemissions, so there is no need to store or otherwise dispose of anybyproducts or toxic fuel. Hydrogen fuel cells have a proven track recordof safe indoor use, such as fuel-cell powered forklifts in materialhandling applications. Furthermore, compressed hydrogen systems arerelatively compact, and can, for example, allow an entire 2 kW to 8 kWsystem to be constructed on a portable cart 14 that will easily fitthrough hotel and building doorways and hallways.

Despite the advantages of using compressed hydrogen gas 20, the systemmay alternatively use a different fuel 22 in combination with a hydrogengenerator 24, (e.g., a reformer) as also shown in FIG. 1 . The output ofthe hydrogen generator 24 is fed to the fuel cell 30 by alternate supplyline 26, just as in the case where hydrogen gas is used directly. As anexample, methanol can be used as a feedstock to produce hydrogen. Oncethe hydrogen fuel is produced in the alternative embodiment, operationof the system is substantially the same.

In an example embodiment, the fuel cell 30 may comprise multiple fuelcells, which are designed to achieve the total voltage output and powerdesired. In each fuel cell of a fuel cell that uses hydrogen as fuel,electricity is generated with no combustion or harmful byproducts, by anelectrochemical reaction that uses, for example, a stack of protonexchange membrane (PEM) fuel cells. PEM fuel cells have a high powerdensity and operate at relatively low temperatures; as a result, theyallow the fuel cell to quickly warm up and begin generating electricity.Other fuel cell technologies may also be used with the present system,such as alkaline fuel cells, zinc oxide, phosphoric acid fuel cells,molten-carbonate, solid oxide, etc.

C. Power Source.

The electrical power generating system 10 may also use a power source100, as shown in FIGS. 13 and 14 . The power source 100 may be orinclude a fuel cell, and may also include a generator that uses fuelsource 102, and may also include electrical storage 40 and one or moreinverters, such as inverter 50. The systems shown in FIGS. 13 and 14 aresimplified for clarity, but can include the components shown in moredetail in FIG. 1 , such as contactor 60 which is used to connect anddisconnect the AC output of the system from a load 92 or the AC main 90.Fuel source 102 may be a local source of fuel, such as gasoline, diesel,kerosene, or bottled hydrogen. The fuel may also be provided over asupply line from a utility, and the fuel can be provided to the powersource 100 by local fuel line 104.

D. DC to AC Conversion.

The electrical storage unit 40 is the first part of the system toreceive power from the fuel cell 30 or power source 100, and it providesfor storage of DC power that is to be provided to the inverter 50 forconversion to AC power. The electrical storage unit 40 may comprise abattery or bank of batteries, which receive and store DC electricalpower to be provided to the inverter 50, as also shown in FIG. 1 .Electrical storage unit 40 receives power from the fuel cell at DC input42, as shown, and provides power via DC outputs 44, which are coupledelectrically (conductively) to inverter 50. Electrical storage unit 40may comprise multiple high-capacity, high-power rechargeable batteriesand a battery charging system (not shown), which receives input powerfrom the fuel cell 30 and conditions it in order to keep the batteriesof the storage unit 40 optimally charged. Electrical storage unit 40 mayalso be used to power the controller 70, as well as other components ofsystem 10, upon startup of the system. Electrical storage unit 40provide for load smoothing, energy storage, and offline energyavailability. During operation of the system, if the system controllerdetects that the batteries in the electrical storage unit 40 are in adischarged state, the fuel cell or generator will automatically go intoan active mode to produce electricity to charge the electrical storageunit 40.

In addition, since the electrical storage unit 40 is connected to theinverter 50, the unit 40 provides power to the inverter 30 along withthat provided by the fuel cell 30, and thus may help the system meethigher transient power demands if the instantaneous power demanded ofthe system exceeds the capacity of the fuel cell 30. The electricalstorage unit 40 also acts as an energy buffer, helping to smooth anyvariability in the output of the fuel cell 30 before it reaches theinverter 50.

The inverter 50 may comprise a single inverter, or it may comprise twoor even more units connected and controlled to operate in parallel. Inany configuration, the inverter 50 is operated under the control ofcontroller 70 to provide an adjustable, preferably sinusoidal AC output52 that can be controlled in phase, frequency, and voltage to match avoltage present on an AC load bus 66, such as building wiring, as bestshown in FIGS. 1 and 2 . More specifically, the output of the inverter50, once synchronized, may readily be connected directly to a standard120/240 volt National Electrical Code building wiring system, and can infact use the existing wiring as a micro-microgrid which can providepower from any of a number of sources to any AC load connected to thewiring system.

The use of a battery (e.g., storage unit 40) in the system provides alocal means to store energy produced by the fuel cell 30 before beingconsumed by the electrical loads being powered. The storage unit 40 thenprovides instantaneous energy delivery, which provides a smoothingfunction for the load as the electrical demand changes in magnitude. Thestorage unit 40 also provides startup power for the fuel cell 30 priorto the consumption of hydrogen for electrical production. The output ofthe storage unit 40 provides inputs to the inverter 50 for theproduction of AC power as well directly providing stabilized DC power(either at voltage at the potential level of the batteries or at anyother DC voltage via the means of a DC/DC voltage converter, regulator,comparator, control logic that manages a feedback loop for producing anoutput voltage that is consistent with a desired target voltage, and/orvoltage division circuitry.)

For applications where the delivered energy is to be an AC waveform,inverter(s) are integrated to convert the DC electricity to ACwaveforms. The AC waveform may be of selectable or adjustable voltage(for example, 120V or 240V), of selectable or adjustable frequency (forexample, 50 Hz or 60 Hz), or phases (for example, single phase or threephase). In certain applications, multiple inverters 50 may be employedto create a plurality of AC voltages, where the settings of the firstinverter (for example, 120V, 60 Hz, single phase) may be different thanthe settings of the second inverter (for example 240V, 50 Hz, threephase).

The AC power output of the system may be a standalone power source for ahouse, building, or for a specific function. In the event that theoutput of the externally-controller electrical power generating systemis to be synchronized with another source or a bus, a synchronizer, suchas synchronizer 106 or a synchronizer within controller 70 is includedfor the phase, voltage, and frequency match of two signals or sources.The synchronizer 106 or controller 70 will independently monitor two ormore electrical power connections, one connection from generating system10 and one connection from the external signal or source that is to besynchronized, and determine a synchronization point when the differencesin phase, frequency, and voltage are minimal. A contactor 60 is closedat the synchronization point, and the two systems are connected to sumthe individual powers to the electrical load.

E. Controller.

The controller 70 performs synchronization and control functionsnecessary for operation of the system 10. Before the system is startedand running, the electrical storage unit 40 provides power to thecontroller 70, which may be off until a power or start button ispressed, at which point the controller begins to operate. The controller70 may control valves and regulators (not shown) used to activate thefuel cell 30. The controller may also be included with power source 100such that power source 100 can receive input from telemetry component 80and provide or receive any outputs or inputs needed for telemetry andcontrol of the system. The controller 70 also receives AC voltage inputsto monitor and control the output of the system, as shown in FIGS. 1 and2 . For example, the controller receives AC input 62 from the output ofinverter 50, to monitor and control the phase, frequency, and magnitudeof the inverter 50. The controller 70 may comprise an analogsynchronizer to bring these voltage parameters into substantialsynchronization with the AC voltage on the AC load bus 66, monitored atinput 64 of the controller 70. Additional details regardingsynchronization and thresholds for closing contactor 60 may be found inU.S. Pat. No. 7,180,210, which is hereby incorporated by reference.

The controller also provides an output command 72 to selectivelyactivate or deactivate a contactor 60. As shown in FIGS. 1 and 2 ,contactor 60 is operable to connect and disconnect the AC output 52 ofthe portable electrical power generating system 10 from the AC load bus66. Although the contactor is shown in the figures as having twocontacts, different configurations are also possible. For example, thecontactor 60 may be configured to connect or disconnect just the activevoltage line, with neutral being directly connected. In addition, thesystem is shown as supplying a single phase, but in practice the systemmay be used with multiple phases or to supply both sides of a 240-volt(three-wire) configuration.

As discussed in greater detail below, when the AC output 52 of theinverter 50 is connected to the AC load bus 66, it is done in a “makebefore break” manner, such that the AC output 52 is connected inparallel with the voltage already present on the load bus 66, whichrequires the synchronization, or substantial matching, of the AC output52 to the voltage on the load bus 66.

In addition to the output control functions, the controller 70 may alsobe adapted to interface with, or to include, a telemetry component 80.If the telemetry is a separate component, it can be adapted tocommunicate with the controller 70 via an internal communication link74, which may be in various forms, such as wired or wireless analogand/or digital links. In addition to the automatic functions of thecontroller 70, the system 10 can use telemetry for remote monitoring andcontrol, which can be done over a communications link 82, such as an airinterface and internet connection, or a wired connection between autility and a customer's house or building, by way of non-limitingexample. An overview of the remote monitoring and control functionalityis best illustrated in FIG. 7 , which shows a remote computing device,such as a smart phone, tablet, laptop or desktop computer, etc., incommunication with three portable generating subsystems A, B, and C,which comprise an electrical power generating system 10 which isconnectable to the load bus 66.

FIGS. 13 and 14 also illustrate an overview of the remote monitoring andcontrol functionality using a utility control system 96, which, again,controls the system through telemetry component 80 in conjunction withcontroller 70. As shown in FIG. 14 , the controller 70 within powersource 100 can control synchronization unit 106, which can synchronizeAC voltages (i.e., phase, frequency, and magnitude) between the powersource 100 and AC main 90, and can also disconnect the AC output usingcontactor 60 (as illustrated in FIGS. 1 and 2 ) to isolate or parallelthe power source 100 from the AC main 90 or a separate AC load 92.

As mentioned above, each subsystem A, B, and C in FIG. 7 may beconfigured substantially as the single unit shown in FIG. 1 , which ispossible because each subsystem can be connected in parallel, and canoperate independently. Accordingly, element numbers followed by letters,such as 62A, are directly equivalent to numbers with no letters, such as62, as represented in FIG. 1 .

As also shown in FIG. 7 , the controller of each subsystem receives ACvoltage inputs to monitor and control the output of the system, and tosynchronize all units with the voltage on the load bus 66.Alternatively, the system may power an otherwise unpowered load bus(e.g., with no AC main source connected) to provide auxiliary,emergency, or backup power.

In the embodiment of FIG. 7 , each subsystem receives AC inputs 62A,62B, or 62C from the output of each inverter, to monitor and control thephase, frequency, and magnitude of the inverter as described above. Eachcontroller 70 may then bring the voltage parameters into substantialsynchronization with any AC voltage on the AC load bus 66, monitored atinputs 64A, 64B, and 64C, as shown. As with the single system connectionof FIG. 1 , each subsystem A, B, or C controls its own contactor, 60A,60B, and 60C, respectively, in order to connect or disconnect thesubsystem AC inverter output from the bus, again using the load bus 66to substantially synchronize of substantially match the voltageparameters so that the systems can be connected in parallel.

FIG. 2 illustrates the system with two subsystems A and B connectable inparallel, where either or both subsystem can provide power to the loadbus 66, either in addition to or in lieu of AC main power source 90, inorder to power load or loads 92. As with the singe system of FIG. 1 ,each subsystem includes an input 62A or 62B (directly equivalent toinput 62 of FIG. 1 ) to monitor and control the inverter output voltage,as well as inputs 64A and 64B to monitor the AC load bus voltage forcontrol purposes. In addition, each subsystem, A, B, has control over acontactor 60A or 60B to connect and disconnect the AC output voltage toor from the load bus 66, using control outputs 72A or 72B, as shown.Since FIG. 2 simply illustrates two of the systems shown in FIG. 1 ,connectable in parallel, the labels appended with “A” and “B” aredirectly equivalent to the inputs, outputs, etc., without thosedesignations as shown in FIG. 1 .

In this configuration, both subsystems can be used to supply power inparallel with the AC main source 90, or alternatively, to supply powerto bus 66 with no AC main power available, in which case subsystem A andB would be synchronized with each other. For telemetry, subsystem A mayuse communication link 82A, and subsystem B may use communication link82B, to receive commands and allow for remote monitoring and control ofthe system.

As shown in FIG. 2 , two or more systems may be connected at the AClevel via a means of synchronization to collectively supply the energyconsumed by the electrical loads. The load sharing between two (or more)fuel cell systems allows the fuel cells to collectively supply theenergy demanded by the load, where the instantaneous load is powered bythe storage unit 40 connected to the loads via the inverter(s) 50, andthe fuel cell(s) recharge the storage unit 40 to full capacity.

F. Operation of Preferred Embodiment.

In use, the electrical power generating system 10 may be connected toexisting building wiring as shown for example in FIGS. 1-3 . To startusing the system, as outlined generally in FIG. 6 , a power button (notshown) may be pressed, which applies power to the controller 70,activating the system, which in turn automatically starts the fuel celloperation. Until the fuel cell is up and running normally (i.e.,providing a DC output to the electrical storage unit 40 and the inverter50) the electrical storage unit 40 can provide power to the system,including the controller 70. At this stage, by default, contactor 60 isdeactivated. The controller then begins to monitor the phase, frequency,and voltage of the AC main power—that is, the voltage on the load bus66, as well as those same parameters at the output of the inverter 50.Initially, there will be a difference in the parameters. For example, asshown in FIGS. 10, 11, and 12 , there may be a difference in thevoltage, the phase, and the frequency, respectively, between the busvoltage and the AC output 52 of the inverter 50. In the figures, thesedifferences are indicated by the arrows.

The controller 70 will continue to monitor the voltages and adjust theoutput of the inverter 50 until the variable voltage parameters of theinverter 50 are within an acceptable threshold. This will allowcontactor 60 to be closed, paralleling the two or more voltage sourceswithout creating large transients on the load bus 66. For example, thefrequency and the voltage may be matched to a close degree, such aswithin a few percent of each other. For phase, an acceptable thresholdmight be a phase difference of 5° or less, with the variable phase ofthe inverter voltage output 52 approaching, rather than moving awayfrom, the phase of the voltage on the load bus 66. Other phasedifferences are also possible, and larger differences may be used,especially if the closing timing is performed by a circuit that detectszero crossings of the AC waveform to close the contactor 60 at or nearzero crossings.

Once the AC output 52 is within acceptable limits, the controller 70will send a command to contactor 60 to connect the electrical powergenerating system 10 to the AC load bus 66, paralleling the inverteroutput with AC main power. This operation is the same whether there isjust one, or multiple, subsystems connected to provide power, as shownfor example in FIGS. 1-3 .

As mentioned above, the telemetry component 80, which may be incommunication with controller 70 via link 74, also allows for remotemonitoring and management of the system 10. It allows a user or users tomonitor and control the system easily using a remote computing device95, such as a smart phone, a tablet, a laptop, or a desktop computer, asjust a few examples. In addition, the system 10 can be controlled andmonitored by an external controller, such as utility control system 96,under the control of a utility company or other entity, to control thesystem 10. The system 10 may communicate with the remote computingdevice 95 via one or more communications or telemetry links 82.Parameters such as run time, remaining fuel amount, power output, outputvoltage, output current, operating temperature, etc., may be monitoredvia telemetry component 80, with the information presented graphicallyor in table form, for example, at device 95. The operating data may alsobe stored locally or in remote device 95 or utility control system 96for reference later. In addition, remote computing device 95 or utilitycontrol system 96 may be used to control the system. Specifically, auser or entity may remotely initiate startup, shutdown, connection, ordisconnection of the electrical power generating system 10 from the loadbus 66. As mentioned above, the remote computing device 95 or utilitycontrol system 96 can communicate with the telemetry component of theelectrical power generating system 10 via wired, wirelesscommunications, or a combination of the two.

FIGS. 3, 8, and 9 represents a particular use of the system 10, which isto provide auxiliary power capacity to building wiring where a higherthan normal load 92 is connected to the AC load bus 66. As shown in thefigures generally, an entire system 10 is typically mounted on a single,portable unit 14, such that it can be easily moved into place, and willfit through doorways and hallways.

In the illustration, the load 92 is a high-powered (e.g., >6 kW) heaterusable for pest remediation in hotel rooms or bedrooms. As shown in FIG.3 , the output of system 10 can be connected through ordinary poweroutlets in a room adjacent to the room with the extra load, in order touse the building wiring 66 as a micro-microgrid. On the load side, theload 92 is also simply plugged in to existing outlets in the room beingtreated, as shown. No special or additional connections are needed,although it may be noted that the building wiring system, without theaddition power of electrical power generating system 10, may not becapable of continuously supplying the power needed at load 92. Note thatthe connections of FIG. 3 are exemplary of a particular use, althoughother uses, such as backup and emergency power generation, are alsopossible as explained herein. For pest remediation, the system 10 mayhave a custom display 12 to show system operating conditions during theremediation, as shown in FIG. 9 .

In particular, for pest remediation using heat, it is required that aminimum temperature is reached and maintained to kill the pests. Toensure effective operation in this regard, the system 10 can receive,via wires or wirelessly, inputs from one or more temperature sensors 94in the room to be treated. The electrical power generating system 10 canbe configured to monitor and display the conditions on a display unit 12during this process. The overall process is outlined in FIG. 8 , andbegins with connecting one or more electrical power generating systems10 to the building wiring, as shown in FIG. 3 .

Next, one or more temperature sensors, such as wireless sensors 94, maybe placed in the room. As an example, they may be spaced apart toprovide a good average temperature, and to ensure there are no coldspots—in other words, to ensure that every location in the room meetsthe temperature requirements for remediation. The system 10 willcontinue to monitor temperatures and provide power to the heater (load92) until a minimum temperature, such as 125° F., is reached by everysensor 94.

Once lethal temperature is reached as indicated by all the temperaturesensors 94, a dwell timer is started, and a visual cue is displayedalong with the dwell time, on display 12. This allows a user to veryeasily see how long the lethal temperature has been applied to the roombeing treated, and to determine if remediation can be consideredcomplete. Note that the parameters shown in FIG. 9 can also easily bedisplayed remotely on remote computing device 95. The display 12 mayalso display the output power level and the total system operating time,as also shown in FIG. 9 .

The example embodiments, for example, as shown in FIGS. 13 and 14 , canalso be used to add onto the existing infrastructure of off-peakelectrical grid management by allowing electrical utility control theexternally-controllable electrical power generating system. In suchcase, the electrical generation system provides distributed generationof electrical power. The system can include a utility control system 96to communicate with telemetry component 80 that manages the remotelylocated power source 100, such as a generator or a fuel cell, and anoptional hydrogen generator or reformer (as shown, for example, in FIG.1 ).

The potential use of a source of electricity other than the electricityprovided by a utility is a worldwide issue. In developing countries, theelectrical grid may be overtaxed or unreliable, and a means for backupgeneration provides reliable power to the point of use. In developedcountries, the means for having distributed generation is importantduring times of excessive demand. The use of existing off-peak gridcontrol allows for reduction of the electrical demand of individualusers during peak demand. If the paradigm was shifted to provideadditional supply, instead of reducing demand, the end user would ableto use the appliances or power they wish, while the demand at theutility is not exceeded.

Perhaps most important is the ability for the example embodiments toprovide electricity in times of emergency. This system 10 can becontrolled at the utility level to provide point of use electricity forindividual users when the supply of electricity from the utility isinterrupted or limited. These instances may occur during floods,blizzards, hurricanes, earthquakes, and tornadoes—natural disasters thatdamage distribution infrastructure between utilities and customers. Incertain cases, such as wildfires in California, utilities haveselectively shut off electricity to customers to minimize the risks ofelectrical components of the distribution network from creating fires.

The example embodiment, as perhaps best shown in FIGS. 13 and 14 ,allows individual customers to have electricity available by localgeneration while the utility company can shut off the electricityflowing through the distribution network that may inadvertently causewildfires, or that needs to be shut down for any other purpose. If afuel cell is used, the output of the system can be safely managedexternally, as there are no moving parts or dangerous heat sources. Allelectrical signals and connections can be managed and may be fullyinsulated to prevent accidental shocks or injury in the even a foreignobject contacts any part of the generating system once it is installed.The utility control system 96 operated by the utility or other entitycommunicates with telemetry component 80, which provides reporting andcontrol functionality both at the site of the installation or at aremote site via wired or wireless communication, or a combination of thetwo.

In some example embodiments, the generator controlled by this inventionmay be fueled by connection to an existing infrastructure supplying afuel, such as a natural gas line or a connection to a propane source,generally denoted as fuel source 102. It is important to note thatduring times where the electrical grid may be interrupted, the naturalgas line or propane line is not under the control of the utility companypowering the electrical grid and is expected to be fully pressurized andoperational.

Using the configuration of FIGS. 13 and 14 , the system can add to theelectrical grid by creating a local supply of electricity, as opposed tothe implementation of off-peak management that shuts off selectedelectrical appliances and loads. The electricity produced by theexemplary embodiments may locally power the appliances (e.g., AC load92) at the point of use, and may also provide electricity at thedistribution level of the grid (e.g., AC Main 90), lowering the demandof the utility to provide electricity to the end user. The telemetrycomponent 80 connects to an external controller, such as utility controlsystem 96, for controlling a power source 100 (which may be aconventional generator with an inverter, for example, or a fuel cell andinverter) to provide AC power, which allows a utility company or otherentity to optional engage or disengage the system.

The design of this system is inherently scalable and modular, allowing asystem to be replicated and combined to create larger implementations.This scalability is seen at the hydrogen input level (where multiplefuel cells may be combined to create a larger electrical source or heatsource. The system may also be scaled at the output of the fuel cells'direct current (DC) voltage output, where individual inverters may beimplemented to create multiple AC circuits. Further, the system is alsoscalable at the outputs of inverter or inverters, where synchronizersthat match voltage, frequency, and phase of alternating current (AC)outputs may be added to increase the availability of electricityproduced at the point of use.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art to which this invention belongs. Although methods and materialssimilar to or equivalent to those described herein can be used in thepractice or testing of the electrical power generating system, suitablemethods and materials are described above. All publications, patentapplications, patents, and other references mentioned herein areincorporated by reference in their entirety to the extent allowed byapplicable law and regulations. In the event of inconsistent usagesbetween this document and those documents so incorporated by reference,the usage in the incorporated reference(s) should be consideredsupplementary to that of this document; for irreconcilableinconsistencies, the usage in this document controls. The electricalpower generating system may be embodied in other specific forms withoutdeparting from the spirit or essential attributes thereof, and it istherefore desired that the present embodiment be considered in allrespects as illustrative and not restrictive. Any headings utilizedwithin the description are for convenience only and have no legal orlimiting effect.

What is claimed is:
 1. An externally-controllable electrical powergenerating system, comprising: a first power source comprising a firstDC output; an electrical storage unit comprising a DC input coupled tothe first DC output of the first power source, the electrical storageunit further comprising a second DC output; an inverter coupled to thesecond DC output of the electrical storage unit to receive power, theinverter comprising a first AC output; a contactor connected between thefirst AC output and an AC load bus, wherein the AC load bus has an ACvoltage; and a controller adapted to sense a phase and a frequency ofthe first AC output and the AC voltage of the AC load bus, wherein thecontroller controls the phase and the frequency of the first AC outputof the inverter; wherein the controller further comprises an outputcommand to selectively activate the contactor when a relationshipbetween the phase and the frequency of the first AC output and the ACvoltage are substantially matched; wherein the controller is furtheradapted to communicate with an external controller operated by a utilityor a managing entity, such that the external controller can enable thecontroller to activate the output command.
 2. Theexternally-controllable electrical power generating system of claim 1,wherein the controller is usable to adjust the phase and the frequencyof the first AC output of the inverter to cause them to substantiallymatch the phase and the frequency of the AC voltage on the AC load busbefore the controller sends the output command.
 3. Theexternally-controllable electrical power generating system of claim 1,wherein the external controller comprises a wireless device.
 4. Theexternally-controllable electrical power generating system of claim 1,wherein the external controller is adapted to send a command to thecontroller to connect the externally-controllable electrical powergenerating system to the AC load bus.
 5. The externally-controllableelectrical power generating system of claim 1, wherein the externalcontroller is adapted to allow a user to monitor operating conditions ofthe externally-controllable electrical power generating system.
 6. Theexternally-controllable electrical power generating system of claim 1,wherein the external controller is adapted to send a command to thecontroller to disconnect the first AC output from the AC load bus. 7.The externally-controllable electrical power generating system of claim1, wherein the external controller is adapted to send a command to thecontroller to shut down the externally-controllable electrical powergenerating system.
 8. The externally-controllable electrical powergenerating system of claim 1, wherein activating the contactor causesthe first AC output to be connected in parallel with the AC voltage onthe AC load bus.
 9. The externally-controllable electrical powergenerating system of claim 1, further comprising: a second power sourcecomprising a third DC output; a second electrical storage unitcomprising a second DC input coupled to the third DC output of thesecond power source, the second electrical storage unit furthercomprising a fourth DC output; a second inverter coupled to the fourthDC output of the second electrical storage unit to receive power, thesecond inverter comprising a second AC output; a second contactorconnected between the second AC output and the AC load bus; and a secondcontroller comprising second inputs adapted to sense a second phase anda second frequency of the second AC output and the AC voltage, whereinthe second controller controls the second phase and the second frequencyof the second AC output of the second inverter; wherein the secondcontroller further comprises a second output command to selectivelyactivate the second contactor when a relationship between the phase andthe frequency of the second AC output and the AC voltage aresubstantially matched.
 10. A method of using the externally-controllableelectrical power generating system of claim 1, comprising: activatingthe first power source; monitoring the phase and frequency of the ACvoltage of the AC load bus; adjusting the phase and frequency of thefirst AC output to substantially match the phase and frequency of the ACvoltage of the AC load bus; and activating the contactor to connect thefirst AC output to the AC load bus.
 11. An externally-controllableelectrical power generating system, comprising: a fuel cell comprising afirst DC output; an electrical storage unit comprising a DC inputcoupled to the first DC output of the fuel cell, the electrical storageunit further comprising a second DC output; an inverter coupled to thesecond DC output of the electrical storage unit to receive power, theinverter comprising a first AC output; a contactor connected between thefirst AC output and an AC load bus, wherein the AC load bus has an ACvoltage; and a controller adapted to sense a phase of the first ACoutput and the AC voltage, wherein the controller controls the phase ofthe first AC output of the inverter; wherein the controller furthercomprises an output command to selectively activate the contactor when arelationship between the phase of the first AC output and the AC voltageare substantially matched; wherein the controller is further adapted tocommunicate with an external controller operated by a utility or amanaging entity, such that the external controller can enable thecontroller to activate the output command.
 12. Theexternally-controllable electrical power generating system of claim 11,wherein the controller is usable to adjust the phase of the first ACoutput of the inverter to cause the phase of the first AC output of theinverter to substantially match the phase of the AC voltage on the ACload bus before the controller sends the output command.
 13. Theexternally-controllable electrical power generating system of claim 11,wherein the external controller is adapted to send a command to thecontroller to connect the first AC output to the AC load bus.
 14. Theexternally-controllable electrical power generating system of claim 11,wherein the external controller is adapted to allow a user to monitoroperating conditions of the externally-controllable electrical powergenerating system.
 15. The externally-controllable electrical powergenerating system of claim 11, wherein the external controller isadapted to send a command to the controller to disconnect the first ACoutput from the AC load bus.
 16. A method of using theexternally-controllable electrical power generating system of claim 11,comprising: activating the fuel cell; monitoring the phase of the ACvoltage of the AC load bus; adjusting the phase of the first AC outputto substantially match the phase of the AC voltage of the AC load bus;and activating the contactor to connect the first AC output to the ACload bus.
 17. An externally-controllable electrical power generatingsystem, comprising: a fuel cell comprising a first DC output; anelectrical storage unit comprising a DC input coupled to the first DCoutput of the fuel cell, the electrical storage unit further comprisinga second DC output; an inverter coupled to the second DC output of theelectrical storage unit to receive power, the inverter comprising afirst AC output; a contactor connected between the first AC output andan AC load bus, wherein the AC load bus has an AC voltage; and acontroller adapted to sense a phase and a magnitude of the first ACoutput and the AC voltage, wherein the controller controls the phase ofthe first AC output of the inverter; wherein the controller furthercomprises an output command to selectively activate the contactor when arelationship between the phase and the magnitude of the first AC outputand the AC voltage are substantially matched; wherein the controller isfurther adapted to communicate with an external controller operated by autility or a managing entity, such that the external controller canenable the controller to activate the output command.
 18. Theexternally-controllable electrical power generating system of claim 17,wherein the controller is usable to adjust the phase and the magnitudeof the first AC output of the inverter to cause them to substantiallymatch the phase and the magnitude of the AC voltage on the AC load busbefore the controller sends the output command.
 19. Theexternally-controllable electrical power generating system of claim 17,wherein the external controller is adapted to allow a user to monitoroperating conditions of the externally-controllable electrical powergenerating system.
 20. The externally-controllable electrical powergenerating system of claim 17, wherein the external controller isadapted to send a command to the controller to disconnect the first ACoutput from the AC load bus.